Most unusual mode of range extension
Most dermatologically useful insect
Most dramatic recovery from near-extinction
Best example of evolution in action
Insects are the most extreme organisms on Earth, and despite their diminutive stature, they wield inordinate power. With the exception of the polar ice caps, every terrestrial ecosystem on Earth is colonised by insects and to some extent controlled by them (and they have made inroads onto the open ocean, too). They dominate the middle ground of virtually every terrestrial food chain or food web.
Insects are extreme in numbers. A single leaf-cutter ant nest, the size of a large camper van buried in the soil, may contain 8 million individuals working together as a single giant super-organism. In the tropical rainforests, termites can reach densities of 10,000 per square metre, a higher density of animal mass than in the largest wildebeest herds of the Serengeti. To produce such numbers, insects are extreme in their fecundity. Egg loads can be counted in thousands and generation times in days. If conditions are right, plagues of biblical proportions can appear as if spontaneously.
Insects are extreme in diversity. Even the experts cannot agree whether there are 3 million different species of insect on the Earth, 10 million, 30 million or 80 million. Compare that to the mere 5,400 known species of mammal. About four-fifths of all the animals yet discovered on our planet are insects: that’s over 1 million species at the last count. And there are many times that number out there awaiting discovery.
Insects are extreme in form. Evolved into the most peculiar shapes and colours, with strange structures and beautiful patterns, even the smallest of these wonderful creatures is magnificent under the microscope. Each has adapted to solve the extreme pressures that arise in the struggle to survive in a world that is dangerous, competitive and unforgiving.
Extreme Insects is divided into three chapters, exploring the nature of the insect universe and looking at some of the most extraordinary creatures in existence.
Extreme Form. In addition to the biggest, smallest, and largest wingspan, we take a look at extreme shapes: spikiest, furriest, shiniest, flattest. Why have such forms evolved? What benefit do they give to the insects that possess them?
Extreme Evolution. Some parts of insect anatomy can appear completely alien to the human eye. They have evolved to allow their possessors a special tool, weapon or means of escape. They have allowed certain insects to survive in extremely difficult or dangerous circumstances. Insects are complex creatures that interact with each other, with their food and with enemies who see them as food. And they get up to some very strange things. They seem to be dancing, skulking or hiding. They brave danger or run like cowards. Some nurture and some murder; some commit suicide. They may appear very clever or extremely dim. Some steal and some give gifts. What is the biological explanation behind these apparently odd behaviours?
Extreme Impact. Humans now reckon themselves to be the dominant life form on Earth, but we have been around for only a few hundred thousand years. Insects were here over 300 million years earlier. Humans, the mere junior upstarts, now come into conflict with a much older and better-established group of organisms. And despite our modern sophistication, we cannot escape such tenacious and apparently determined animals. They invade our fields, our houses and even our bodies. Some we can tame for our own uses, but with others we are still at war.
Insects are both awful and awe-inspiring, certainly worthy of our respect and our study. They give us a window on the natural world through which we can see, and attempt to understand, the environment in which we live, indeed of which we are an integral part. The huge numbers of insects, and their depredations on human food and health, are sometimes bemoaned. In reality, they form a vast biomass, and it is a wasteful shame that insects form an insignificant part of the human diet. We may not eat them very often, but insects offer a more philosophical sustenance – food for thought. In their study, there is a veritable feast for the mind.
Richard Jones
London, September 2009
Oldest insect • Biggest insect • Longest insect • Whitest insect • Shiniest insect • Slimiest insect • Biggest blockhead • Most sexually dimorphic insect •